Tree jack



Feb. 9 1926.

L. WATSON ET AL TREE JACK Filed July 21, 1925 lNl/KNTOBS L MIME/7E6VVdlffQ/Z AIL/51777 Q M/dd/fiW/JJ ATTORNfY Patented Feb. 9, 1926.

UNITED STATES PATENT OFFICE.

TREE JACK.

Application filed July 21, 1925. Serial No. 45,027.

To all whom it may concern:

Be it known that'we, LAWRENCE Mason and AUSTIN O. MIDDLEMISS, citizensof the United States,residing in Vancouver,county of Clarke, and Stateof Washington, have invented a new and useful Tree Jack; and we dohereby declare that the following is a full, clear, and exactspecification, such as will enable others skilled in the art to which itappertains to make and use the same. i

The invention is a jack that is particularly adaptable for falling treesor the like.

The object of the invention is to provide a small sturdy jack with aswivel head that may be placed in a small uneven space and that willexert a great pressure for a short distance.

Another object of the invention is to provide a small sturdy jack whichis of a light weight and at the same time durable.

And a further object of the invention is to provide a small sturdy jackof a simple and economical construction.

\Vith these ends in view, the invention embodies a cylindrically shapedbase with threads on its outer surface, a cylindrically shaped cap witha curved top and threads on its inner surface, and a head slidably heldin an opening in the center of the ca 3.

Other features and advantages of the in vention will appear from thefollowing description, taken in connection with the drawings, whereinFigure 1 is a vertical section through the 'ack.

1 Figure 2 is a View looking toward the lower side of the cap.

In the drawings, we have shown our device as it would be made whereinnumeral 1 indicates the base, numeral 2, the cap and numeral 3 the head.

The base 1 may be cylindrically shaped as shown with the upper end openand the lower end closed, teeth at on the bottom and threads 5 in itsouter surface. 7

The cap 2 is also cylindrically shaped with its lower end open and itsupper end provided with a curved surface 6 having an opening 7 in thecenter, its inner surface provided with threads 8 to correspond withthreads 5 of the base and its outer surface provided with lugs 9 bywhich it inlay be gripped by a spanner wrench or the li (e.

The head 3 is made of a solid circular piece of material with its undersurface 10 curved to correspond with the upper surface of the section 6and its upper surface provided with projections or teeth 11 similar tothe teeth 4. In the center of the under side of the head 3 is a bolt 12with its outer end threaded and provided with a nut 13 for holding awasher 14: against the inner surface of the section 6. It will beobserved that by turning the nut 13, the friction between the washer andthe under side of the section 6 may be adjusted.

It will be understood that changes may be made in the constructionwithout depart ing from the spirit of the invention. One of whichchanges may be in the design of either of the'members, another may be inthe use of other means for rotating the cap, and still another may be inthe use of'other means for attaching the head to the cap.

The construction will be readily understood from the foregoingdescription. To use the device, the cap may be screwed down upon thebase and when used for logging and particularly for falling and buckingtimber, it will. be placed in a notch in a saw cut and it will beobserved that as the cap is unscrewed or turned so that it will moveupward, it will exert a tremendous pressure thereby eliminating wedgesor the like. Although this device is particularly designed for this use,it is understood that it may be used for any similar work or for anyother purpose.

Having thus fully described the invention, what I claim as new anddesire to secure by Letters Patent, is

In a lifting jack, a cylindrically shaped base with threads on the outersurface, a cylindrically shaped cap with threads 011 the inner surfaceto correspond with the threads of the base, and means on the outersurface of the cap by which it may be rotated, said cap having a curvedupper surface with an opening in the center and a head with a stemprojecting through the opening of the cap, said stem having means at itsinner end for adjustably and slidably holding the head to the cap.

LAWRENCE WATSON. AUSTIN O. MIDDLEMISS.

